Cylinder with a rubber cover

ABSTRACT

An inking cylinder or a dampening cylinder or roller for a rotary printing press is provided with a rubber cover that is adhered to the body of the cylinder or roller. A device for applying the rubber cover to the roller body includes a support table that is pivotably supported.

FIELD OF THE INVENTION

The present invention relates to a cylinder with a rubber covering, aswell as to a device for applying the rubber covering.

DESCRIPTION OF THE PRIOR ART

It is known to coat a cylinder with rubber, for example by vulcanizing.

It is disadvantageous here that it is necessary to finish the surface ofthe rubber covering, for example by grinding. This, in turn, leads torelief formations on the surface of the rubber covering, so thatirregularities are caused when transferring liquid or pasty materials.

EP 0279295 A2 describes an inking system of a printing press, wherein aninking roller is provided with a rubber blanket.

DE 19517653 A1 discloses a roller for a printing press, whose basic bodyis enclosed in a hose made of an elastomeric material.

SUMMARY OF THE INVENTION

The object of the present invention is based on providing an inking ordampening agent roller with a rubber coating, as well as to a device forapplying the rubber coating.

In accordance with the present invention, this object is attained by theprovision of an inking and dampening agent roller having a roller bodywith a rubber covering. The covering consists of a finite rubber blanketwhose entire underside is adhesively bonded to the roller body. A jointline formed by the start and end of the rubber covering is angled withrespect to the axis of rotation of the roller.

The advantages to be obtained by the present invention lie, inparticular, in that an essentially homogeneous surface of the rubbercovering fastened to the basic roller body is achieved. This, in turn,has the result that the even transfer of pasty or liquid materials isassured.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention is represented in thedrawings and will be described in greater detail in what follows. Shownare in:

FIG. 1, a cross sectional view with a schematic representation of an inkapplication roller with a rubber covering in a short inking system, aswell as a device for applying the rubber covering;

FIG. 2, a view from above of the roller in FIG. 1 in an enlargedrepresentation, and in

FIG. 3, an enlarged detail in accordance with FIG. 1.

DESCRIPTION 0F THE PREFERRED EMBODIMENT

A short inking system 1 for a rotary printing press consists, forexample, of a printing or rubber blanket cylinder, not specificallyrepresented, and a forme cylinder 2, to which pasty ink is transferredfrom a screen roller 4 by means of an ink application roller 3, asdepicted in FIG. 1. The screen roller 4 is supplied with ink by achamber doctor blade installation 6. An ink collecting pan 7 is arrangedunderneath the chamber doctor blade installation 6. The above mentionedelements are seated fixed in a lateral frame, not specifically shown.

The ink application roller 3, hereafter referred to as roller 3,consists of a basic roller body 8 with two shaft journals 9, whichrotate around an axis of rotation 11, as may be seen in FIGS. 1 and 2. Aself-adhesive rubber blanket 13 of a thickness “b”, for example, of 2.3mm, is situated on the entire surface or surface area 12 of the basicroller body 8. A double-sided adhesive foil, or an application ofadhesive of a thickness of approximately 0.3 mm can be provided here. Bymeans of this adhesive or adhesive foil it is achieved that the rubberblanket 13 is glued on its entire underside on the surface area 12.

The rubber blanket 13 is envelope-like and has a start 14 and an end 16.After having been applied to the roller 3, the start 14 and the end 16meet along a separation or joint line 17 and may form a butt joint.Referred to an unrolled rubber blanket 13, this joint line 17 extends atan angle α in relation to a line 18 extending parallel to the axis ofrotation 11 of the basic roller body 8, as may be seen in FIG. 2. Theangle α lies between greater than zero degrees and six degrees, andpreferably at three degrees.

In accordance with further preferred embodiments, the start 14 and theend 16 of the rubber blanket 13 can overlap in the form of an offsetjoint or a tapered overlap joint. For this purpose, the start 14 and theend 16 each have tabs 21, 22, which are designed to be of reducedthickness, for example of five to ten millimeters, and which are placedon top of each other in a joint area 19 as seen most clearly in FIG. 3.The rubber blanket material is known and is commercially available foruse with a rubber blanket cylinder in offset rotary printing presses.

The rubber blanket 13 is applied as follows: a rubber blanket support,for example a table 23, is made of a profiled iron frame having twospaced apart longitudinal guides 24, only one is represented , which areconnected by means of three transverse profiles 26, 27, 28.

The table 23 is covered on its surface, for example with sheet metal 29.The transverse profiles 26 and 27 are arranged directly to the left andright under the roller 3, so that in this strip-shaped area a specialresilient effect and good adaptation to the radius is achieved by meansof the sheet metal 29.

The table 23 is pivotably supported by means of bolts 31 in the notrepresented lateral frame of the rotary printing press at about half itslength “1”. As depicted in FIG. 1, a rubber blanket 13—shown in dashedlines—is placed on the table 23 with the side coated with adhesivefacing up. A detent strip for the start 14 of the rubber blanket 13 canalso be provided parallel with the transverse profiles 26, 27, but onthe side of the sheet metal 29 opposite to profiles 26 and 27

After the roller 3 has taken up a correct register position, the end 32of the table 23 which is remote from the roller is pushed into a lowerposition D. The roller is rotated at creep speed in the clockwisedirection E until, after a complete revolution of the roller 3, therubber blanket 13 has been completely applied to the basic roller body8.

Thereafter, the table 23 is pivoted upward in the direction C, orrespectively lifted out at the bolts 31. A quick-setting adhesive, forexample, is applied in the axis-parallel direction between thestrip-shaped tabs 21, 22, and the facing sides of the tabs 21, 22 areplaced on top of each other and caused to adhere by pressing them downfor approximately 10 to 20 seconds. The pressing can take place, forexample, in that the table 23 is turned by 180°, and is re-suspendedfrom the bolts 31 in such a way that the end 32 is underneath the roller3. In the course of this, a strip 33 of foam rubber can be pressed onthe joint area 19.

If the joint line extends at an angle α in respect to the line 18, thejoint area 19 is enlarged to form an even wider joint area 34.

In accordance with another preferred embodiment which is notspecifically represented table 23 can also be arranged to be movable bymeans of a frame, i.e. not fixed in the lateral frame.

To fasten or position the rubber blanket 13 at the correct registermeans that the joint area 19, or respectively 34, of the cylinder 3corresponds, as much as possible, with a print-free strip, for example acylinder channel 36 of the plate cylinder 2. It is advantageous if thecircumferential width of the cylinder pit 36 is greater than the jointarea 34.

The roller 3 can be used as a rubberized inking roller or as arubberized damping agent roller with dampening systems. In this case,the roller 3 can be preferably placed directly against a forme cylinder,for example the plate cylinder 2.

The hardness of the rubber blanket is 65 to 70 Shore. While preferredembodiments of a cylinder with a rubber cover and a device for applyingthe cover in accordance with the present invention have been set forthfully and completely hereinabove, it will be apparent to one of skill inthe art that a number of changes in, for example, the overall size ofthe cylinder, the specific type of rotary printing press and the likecould be made without departing from the true spirit and scope of thepresent invention which is accordingly to be limited only by thefollowing claims.

What is claimed is:
 1. An inking and dampening agent roller for a rotaryprinting press comprising: a roller body having a roller body surfaceand an axis of rotation; a rubber covering on said roller body, saidrubber covering being formed by the placement of a finite length rubberblanket onto said roller body surface, said finite length rubber blanketincluding an underside, a start and an end; an adhesive bond betweensaid underside of said finite length rubber blanket and said surface ofsaid roller body; and a joint formed by the meeting of said start andsaid end of said finite length rubber blanket placed on said roller bodysurface, said joint defining an angled joint line, said angled jointline extending at an angle between greater than 0° and 6° on said rollerbody surface with respect to said axis of rotation of said roller body.2. The inking and dampening agent roller of claim 1 wherein said rubberblanket is self-adhesive.
 3. The inking and dampening agent roller ofclaim 1 wherein said roller body is provided with an adhesive.
 4. Theinking and dampening agent of roller 1 wherein said rubber covering canbe brought into rolling contact with a screen roller and a formecylinder of the rotary printing press.